Clade | Phylogenetic group including all the descendents from a common descendent |
Assumptions of Cladistics | - Any group of living things are related by a common ancestor
- Lineages only bifurcate
- Changes occur in every lineage over time |
Monophyletic Group | Clade including all common descendents of an ancestor |
Paraphyletic Group | Group including some but not all descendents from a common ancestor |
Polyphyletic Group | Group of similar organisms which do not share a directly common ancestor |
Phylogenetic Tree | Diagram representing the evolutionary steps of a species |
Difference between Phylogram and Cladogram | Phylogenetic tree represents the relation of different organisms relative to evolutionary time along with the amount of variations occurring within that time.
Cladogram only represents the common ancestral relationships between organisms |
Protein Relatedness | Comparison of amino acid sequences in proteins to identify similarity, even across distantly related species.
[Fewer differences between organism's protein amino acid sequences then there are between nucleotide sequences since DNA changes do not always result in amino acid mutation] |
DNA Hybridisation | Single-stranded DNA absorbs UV light, double-stranded doesn't since DNA separates at 87°C [every 1°C difference under 87°C and separation is a 1% difference] |